In U.S. Pat. No. 5,133,828 the disclosure of which is hereby incorporated by reference herein, a reversible pressure sealer, and method of handling business forms utilizing a pressure sealer, are provided. The invention in that patent shows a set of reversible rollers which pass the business forms through them in a first direction, and then reverse and pass them in the second direction, opposite the first direction. The advantageous reversing rollers described in the above-mentioned patent are used in this invention, except that the rollers are located so that at least two perpendicular edges--and in the preferred form all four edges--of the business form may be conveniently sealed either manually or semi-automatically. This allows for higher speed action on business forms (that is producing more sealed business forms per minute), than for the arrangement in the above-identified patent, while still employing all the advantageous features thereof.
According to one aspect of the present invention, a method of handling business forms, each having at least first and second perpendicular strips of pressure sensitive adhesive of a predetermined width for affixing one part of each business form to another, is provided. The method utilizes a machine having a first set of rollers rotatable above parallel first and second axes, and having a second set of rollers rotatable above parallel third and fourth axes substantially perpendicular to the first and second axes, which rollers apply a sealing force at a nip. The method comprises the following steps: (a) Feeding a business form into operative association with the nip of the first set of rollers, with the first strip of adhesive aligned with the nip. (b) Rotating the first set of rollers so that the business form is driven through the nip in a first direction, a sealing force being applied by the first set of rollers to the predetermined width of adhesive of the first strip. (c) Just prior to the form being drive completely through the nip, stopping rotation of the first set of rollers, and reversing the direction of rotation thereof, so that the business form is driven through the nip in a second direction, opposite the first direction. (d) After the business form has been driven through the nip of the first set of rollers in the second direction, passing the form into operative association with the nip of the second set of rollers with the second strip of adhesive aligned with the nip. (e) Rotating the second set of rollers so that the business form is driven through the nip in a third direction, substantially perpendicular to the first and second directions, a sealing force being applied by the second set of rollers to the predetermined width of adhesive of the second strip. (f) Just prior to the form being driven completely through the nip, stopping the second set of rollers, and reversing the direction of rotation thereof so that the form is driven through the nip in a fourth direction, opposite the third direction. (g) After step (f), removing the form from association with the rollers.
There may also be the further step (h), between steps (c) and (d), of rotating the form 90 degrees about an axes parallel to the first and second axes; or, the form may be led without rotation from the first set of rollers to the second set of rollers between steps (c) and (d). Typically the rollers are narrow-width rollers which apply a sealing force only to the approximate area of the predetermined widths of adhesive. The first through fourth axes may be substantially horizontal, and a form may drop vertically downwardly between steps (c) and (d).
According to another aspect of the present invention, an apparatus for applying pressure to business forms to activate pressure sensitive adhesive associated with the forms is provided. The apparatus comprises the following elements: A first set of rollers rotatable about parallel first and second axes and biased together to form a first nip. First reversible drive means for driving at least one of the first set of rollers alternately clockwise and counterclockwise. First sensor means for sensing the position of a business form with respect to the first and second rollers. A second set of rollers rotatable about parallel third and fourth axes, and biased together to form a second nip. Second reversible drive means for driving at least the second set of rollers alternately clockwise and counterclockwise. Second sensor means for sensing the position of a business form with respect to the second set of rollers. The third and fourth axes being disposed substantially perpendicular to the first and second axes. And, control means connected to the first and second sensor means and the first and second reversible drive means for driving a business form sensed by the sensor means through the first nip in a first direction so that compression sealing force is applied thereto, and after the business form has passed almost completely through the first nip, in a second direction, reversing the first drive means to drive the business form through the first nip again in a second direction, opposite the first direction; then for driving a business form sensed by the second sensor and through the second nip in a third direction, so that a compression sealing force is applied thereto, and after the business form has passed almost completely through the second nip in a third direction, reversing the second drive means to drive the business form through the second nip again in a fourth direction, opposite the third direction.
All of the axes may be horizontal, or the first and second axes may be substantially horizontal, and the third and fourth axes substantially vertical. It is desirable to provide narrow-width rollers, although full-width rollers may be suitable under some circumstances. Also a conveyor may be associated with the second set of rollers for driving forms to the rollers in the third direction, and away from the rollers after discharge therefrom, in the fourth direction.
It is the primary object of the present invention to provide the effective, quick, pressure sealing of business forms. This and other aspects of the invention become clear from an inspection of the detailed description of the invention and from the appended claims.